/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

/*
 * THE FILE HAS BEEN AUTOGENERATED BY MSGTOOL TOOL.
 * All changes made to this file manually will be overwritten 
 * if this tool runs again. Better make changes in the template file.
 */

package org.apache.harmony.luni.internal.nls;

import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;

/**
 * This class retrieves strings from a resource bundle and returns them,
 * formatting them with MessageFormat when required.
 * <p>
 * It is used by the system classes to provide national language support, by
 * looking up messages in the <code>
 *    org.apache.harmony.luni.internal.nls.messages
 * </code> resource bundle. Note that if this file is not available, or an
 * invalid key is looked up, or resource bundle support is not available, the
 * key itself will be returned as the associated message. This means that the
 * <em>KEY</em> should a reasonable human-readable (english) string.
 * 
 */
public class Messages {

	// ResourceBundle holding the system messages.
	static private ResourceBundle bundle = null;

	static {
		// Attempt to load the messages.
		try {
			bundle = setLocale(Locale.getDefault(),
					"org.apache.harmony.luni.internal.nls.messages"); //$NON-NLS-1$
		} catch (final Throwable e) {
			e.printStackTrace();
		}
	}

	/**
	 * Generates a formatted text string given a source string containing
	 * "argument markers" of the form "{argNum}" where each argNum must be in
	 * the range 0..9. The result is generated by inserting the toString of each
	 * argument into the position indicated in the string.
	 * <p>
	 * To insert the "{" character into the output, use a single backslash
	 * character to escape it (i.e. "\{"). The "}" character does not need to be
	 * escaped.
	 * 
	 * @param format
	 *            String the format to use when printing.
	 * @param args
	 *            Object[] the arguments to use.
	 * @return String the formatted message.
	 */
	public static String format(String format, Object[] args) {
		final StringBuilder answer = new StringBuilder(format.length()
				+ (args.length * 20));
		final String[] argStrings = new String[args.length];
		for (int i = 0; i < args.length; ++i) {
			if (args[i] == null) {
				argStrings[i] = "<null>"; //$NON-NLS-1$
			} else {
				argStrings[i] = args[i].toString();
			}
		}
		int lastI = 0;
		for (int i = format.indexOf('{', 0); i >= 0; i = format.indexOf('{',
				lastI)) {
			if (i != 0 && format.charAt(i - 1) == '\\') {
				// It's escaped, just print and loop.
				if (i != 1) {
					answer.append(format.substring(lastI, i - 1));
				}
				answer.append('{');
				lastI = i + 1;
			} else {
				// It's a format character.
				if (i > format.length() - 3) {
					// Bad format, just print and loop.
					answer.append(format.substring(lastI, format.length()));
					lastI = format.length();
				} else {
					final int argnum = (byte) Character.digit(
							format.charAt(i + 1), 10);
					if (argnum < 0 || format.charAt(i + 2) != '}') {
						// Bad format, just print and loop.
						answer.append(format.substring(lastI, i + 1));
						lastI = i + 1;
					} else {
						// Got a good one!
						answer.append(format.substring(lastI, i));
						if (argnum >= argStrings.length) {
							answer.append("<missing argument>"); //$NON-NLS-1$
						} else {
							answer.append(argStrings[argnum]);
						}
						lastI = i + 3;
					}
				}
			}
		}
		if (lastI < format.length()) {
			answer.append(format.substring(lastI, format.length()));
		}
		return answer.toString();
	}

	/**
	 * Retrieves a message which has no arguments.
	 * 
	 * @param msg
	 *            String the key to look up.
	 * @return String the message for that key in the system message bundle.
	 */
	static public String getString(String msg) {
		if (bundle == null) {
			return msg;
		}
		try {
			return bundle.getString(msg);
		} catch (final MissingResourceException e) {
			return "Missing message: " + msg; //$NON-NLS-1$
		}
	}

	/**
	 * Retrieves a message which takes 1 character argument.
	 * 
	 * @param msg
	 *            String the key to look up.
	 * @param arg
	 *            char the character to insert in the formatted output.
	 * @return String the message for that key in the system message bundle.
	 */
	static public String getString(String msg, char arg) {
		return getString(msg, new Object[] { String.valueOf(arg) });
	}

	/**
	 * Retrieves a message which takes 1 integer argument.
	 * 
	 * @param msg
	 *            String the key to look up.
	 * @param arg
	 *            int the integer to insert in the formatted output.
	 * @return String the message for that key in the system message bundle.
	 */
	static public String getString(String msg, int arg) {
		return getString(msg, new Object[] { Integer.toString(arg) });
	}

	/**
	 * Retrieves a message which takes 1 argument.
	 * 
	 * @param msg
	 *            String the key to look up.
	 * @param arg
	 *            Object the object to insert in the formatted output.
	 * @return String the message for that key in the system message bundle.
	 */
	static public String getString(String msg, Object arg) {
		return getString(msg, new Object[] { arg });
	}

	/**
	 * Retrieves a message which takes 2 arguments.
	 * 
	 * @param msg
	 *            String the key to look up.
	 * @param arg1
	 *            Object an object to insert in the formatted output.
	 * @param arg2
	 *            Object another object to insert in the formatted output.
	 * @return String the message for that key in the system message bundle.
	 */
	static public String getString(String msg, Object arg1, Object arg2) {
		return getString(msg, new Object[] { arg1, arg2 });
	}

	/**
	 * Retrieves a message which takes several arguments.
	 * 
	 * @param msg
	 *            String the key to look up.
	 * @param args
	 *            Object[] the objects to insert in the formatted output.
	 * @return String the message for that key in the system message bundle.
	 */
	static public String getString(String msg, Object[] args) {
		String format = msg;

		if (bundle != null) {
			try {
				format = bundle.getString(msg);
			} catch (final MissingResourceException e) {
			}
		}

		return format(format, args);
	}

	/**
	 * Changes the locale of the messages.
	 * 
	 * @param locale
	 *            Locale the locale to change to.
	 */
	static public ResourceBundle setLocale(final Locale locale,
			final String resource) {
		try {
			final ClassLoader loader = null;
			return (ResourceBundle) AccessController
					.doPrivileged(new PrivilegedAction<Object>() {
						@Override
						public Object run() {
							return ResourceBundle.getBundle(
									resource,
									locale,
									loader != null ? loader : ClassLoader
											.getSystemClassLoader());
						}
					});
		} catch (final MissingResourceException e) {
		}
		return null;
	}
}
